persson



0. F. PERSSON.

VARIABLE FITCH PROPELLER.

APPLICATION man lum: 25.19113.

Wim e'sses @www Patented Sept. 23, 1919.

3 SHEETS-SHEET I.

lll/I lll/lll Im/ento r I Otto?. Persson,

HsJClttorDQg.

0. F. PERSSON.

vAmALE Pncu PROPELLER. A APPLICATION FILED IL'NE 25| I9IB. r

Patented Sept. 23, 1919.

3 SHEETS-SHEET 2.

Inventor Otto F. Persson,

Hsqttorney.

0. F. PERSSON. VARIABLE Pnc'H PnoPELLER.

APPLICATION FILED 1Ll Patented Sept. 23, 1919.

3 SHEETS-SHEEI 3.

Inventor ,Otto F. Persson, bg:waf

ALL

1 1 I VII... ,I

HisJfItLornqg.`

50 l .--projections 11 as a citizen of the United i T all whom z'tmay i *En srniiis Para foreros.

or'r'o F. rnnssoir, br ERIE, PENNSYLVANIL VARIABLE- FITCH PROPELLE.

concern.' Y

Be it known that I OrroF. BENSON, a tates, residing at Erie, inv the county 'of Erie, 'State' of Pennsyl-I vania, have invented certain new and useful Improvements in Variable-Pitch Propellers,

of which the following is a specification.

{,Ihe present invention relates to-variable pitch pro'pellers and4 especially to those inntended for driving aeroplanes but' is alsov 7applicable to the propulsion'of vessels whose travel is wholly or partially inthe water.

which the 4 while on the other hand the The gobject" of my inventionis to provide i a propeller of improved construction in blades are so constructed and arranged that their angles can be changed for the purpose of varying the speed ofthe ob- ]ect propelled thereby; and in the case of a vessel Aso changed that the direction of its ,movement can' be reversed. One of the ii iiv portant features of my improvedlconstrucf tion 'is the arrangement, of parts whereby the' blades can be adjusted about their axes without thev expenditure of much energy stresses and shocks to which the blades are subjected are prevented from being freely` transmitted.l to v the operating handle or otherdevice.

For a consideration ,of what AI believe to be novel and my'inventon, attentionis direct'ed to the accompanying description and In the drawings which .are illustrative of my invention Figure 1 isa cross-section of aA four-.bladed propeller for an aeroplane; Fig. 2 is an axial section of the same;l Fig. 3 is a view in elevation of rthe propeller;

Fig; 4 is a view showing vthe propeller and its engine in side elevation; Fig. 5 is a 'modified form ofthe invention in axial section\ showin the adjusting mechanism o f a'two-blade 4propel1er;11`ig. 6 is .a crosssection of the same; Fig. 7 1s a view in elevation of a propeller for a vessel, and Fig. 8

is an axial view of the same showing the' blade adjusting means.

10 indicates the shaft of va prime mover such as an internal combustion engine or turbine. Secured to one end of itis a casing having as many radially extending tubular former being keyed to1 the there are propeller blades.l l1.-',1`he casing is made in two principal parts V12 and 12, the

""sliaft and.jthe latter securedv to the first Mounted on each tubular projectionis a propeller blade 14 of suitable shape and size for the work to be performed. The blades may be of `any suitable construction. In the present case each comprises a base which has a hollow spindle 15 formed integral therewith. On each spindle are two collars orshoulders 16 andt17, the former engaging an inner shoulder on the casing and the latter the finished outer face thereof. These 'collars prevent endwise movement ofthe blades and the collar 16 serves to `resist centrifugal stresses.

The casing as before stated is in two parts x Specilcation of Letters Tatent. l Patented Sept. 23, 1919. f Application tiled June 25, 1918. Serial No. 241,855. i i

and the plane of division coincides with the axes of the blades and hence by takin out` the bolts 13, the parts canpbe separate and the blades easily removed. Formed inte ral with the spindle is a,u portion 18 whic is made hollow to reduce its weight and mounted thereon is the'blade proper. In this case the blade is made'of relatively thin metal to reduce. the weight and is secured to the .part 18 by any appropriate means.

. The inside ofthe spindle has a number of spirally arranged threads which mesh with corresponding threadsy on the blade actuator. In other wordsfea'ch spindle in addition to acting as s uch forms ay nut having screw threads of such character that when the cooperating screw is moved lon 'tudinally thereof, the spindle and nut wil be turned angularly about their axes. The blades are provided with actuators arranged in pairs. Each actuator comprises a portion l9having spirally arranged screw threads adapted for -engagement with those in the nut in the spindle. "Moving the screwiactuator toward or away from the main shaft causes an angular movement of the spindle and blade in one directionlor the other and in this manner changes the effective angle or pitch of the blade to cause a greater or lesser provlvpulsive effect. Each screw 19 is formed integrallyjwith or'is rigidly attached to a f the main shaft and is held in position by a: suitably arranged guide 21. The /comanion rack on the oppositeside of the shaft sliding rack`.20 which is located at one sideL ls'held in place by a similar guide 21.*The

y second pair of racks are arranged at right 4angles to the first and have guides 26 of a Vconstruction similar to those described but extending at right angles thereto. All of .'these guides are formedintegral with the casing and being arrangedin the form of a,

Q' ii hollow square render thecasing very strong without being heavy.

yMounted on the-,main vshalt and extend-V ingthrough the part 12aof the casing is a sleeve 28 which is held from turnin independently of the shaft by the spl1ne29. On the sleeve is mounted a grooved collar 30 which' isl retained lin ,place between a shoulder anda clamping nut. n the Vdln.- ner end of the sleeve is formed the spiral gear 31, the'angle of the teethv 32 being cause thelatter to change'theangular poshown in dotted lines in Fig. 2. 'Ihe angle sitionor'pitchj--ofthe blades .to obtain theof the gear teethissuch that axial'l move,- desired/propulsiye -eliect will` be. seen ments of the gearcauseslengthwise ymovef 2that the same irreversible arrangenrent ofL ments of the racks and is also such that the: Aparts is providedinthis eonstruction as in l,8 gear cannot be moved by reason of pressure I the one'jpreviously described butthat it is car:

s threads which coperate .with threads in `the interior of the nut 40.y s ,f

Ihe action is as follows :-When the shaft 10 rotates'it drivesthe blades in {the usual manner. To change the angle of the blades 7 -the position of the gear 31 is adjusted longi- NtudinaHy. rlhis in turn moves the nuts 40/ longitudinally but 'in a direction vat right 'angles to the shaft axis 'and inso doing its threads actingc o n those of the screws 44 7 exerted by the' rack teeth.- Thi's'gear is so.;A

gages and actuates all four racks simule taneously. As will-be seen the raclswhich actuate one pair of blades are located iin the same plane and engage one end of the gear, while the racks' which actuate'the other pair of blades are located in a parallel planea'nd engage the other'endof the gear. kx j In order to change the angular positions of the blades a forked lever 33, Fig. 4, is mounted on the enginev 34 or other support and engages the grooved collar on opposite sides. The lever is actuated by. a 4rod 35, connected to a suitablejhandle, from a.

the 4sleeve and spiral gear endwise causesf in -so ,doing spindles to assume new suitable place near the operatori Moving the teeth of the latter tomove the racksfin `or out as the case may be. The racks in turn move the screws 19-longitudinally and cause the blades and their angular positions., It will be seen that the reciprocating movements of thej racks 'are at ri'g'ht angles" to those of the sleeve,

ments of the spirally threaded screws 19 re" sult in angular movements ofthe blades.`

' The angles of the teethand threads are such lFigs. 5 and 6, the casin that the sleeve and gear can adjust the an-iiV/iith the blades but the blades gular positions of themselves cannot move the gear and sleeve. In other words,7 an irreversible actuating 'mechanism is aranged between the sleeve4 and blades. y

Referring to the arrangementmshown in is made in two arts as before but the lade'sinst'ead of eing `radial are slightly olii-set from thev axis of the main shaft l0. Splined on the main shaft is the'sleeve 28, which carries the gear 31, the angular relation of the teeth being illustrated at 32, Fig. 5. 40 indicates a nut arrangedto move longitudinally in ides 41. On one side of the nut are ormed rack'teeth 42 vwhich mesh with the teeth on the ygear. -31. The spindle 43 of" each blade is made Solid in. this case and formed thereonl or rigidly secured thereto is a screw 44 having lengs'pirally arranged..

and l that similar move- '.nariiy t riedout in a slightly different manner. positioned and of such length that 1t en-` In Figs.' 7 and 8 my inventionis shown applied to the propeller of a vessel, the construction lof the propeller 'being essentially the 'fsame as desribed in connection with Figs. 1 and 2. 45 indicates/thel hull of the.'v

of the casing llonger and where it .terminates inside the water.` `It is to be notedthat the sleeve 46 vessel. is provided with a circular rack 49.

Meshing with the rack -is gear 5 0 which is mounted on a cross-shaft 51. On the shaft"- is also mounted a worm wheel 52 meshing with a worm driven by an electric or 'other motor 52. By adjustingthesleeve 28 the pitch of the bladesvv can'be changed as desired, -the range of movement being'sulii.A cient to cause the rection of movement of4 the vessel. For small boats the blades can 'be reversed by in' the` manner described in connection s. 1 to 4; conversely power means can-be employed for adjusting the angles, of theblades for aeroplane pl this is not necessary.

opellers but ordi- In accordancefwiththe provisions of the patent statutes,' I have described the prin-v together 4with the apparatus/which I now consider to 'represent the. best .embodiment thereof, but

ciple of .operation'of my invention,

I desire to have it understood that the apparatus shown is only-illustrative-,- and that izo the invention canbe carried out by other mGa/IIS.

g shaft, a casing,

- What II claim as new and desire to secure I rigidlyl aftachedf to 4the shaft, propeller Y blades mounted on Ithe'casing fwhich' are capable of angular adjustment, a member 'splined on the shaft, which is capableof.

.rigidly attached to thel shaft,

said reciprocating movements into angular movements of the blades.

2. In a device of the character described, the combination of a driving shaft, a casing propeller blades mounted on the casing whic are capable of, angular adjustment, a gear member splined on the shaft which is capable of laxial movement independent of the shaft,` racks located in the casingrwhich are recip' rocated in a direction perpendiular to the shaft by the gear member, and irreversible on the shaft and havin `spiral perpendicularly means which transform the reciprocating movements of the devices into angular motion and turn the blades on their axes without changing their diameter.

3." In a device of the character described,

the combination of a driving shaft, a casing rigidly attached thereto,

propeller blades carried by the casing, a sliding ear splined y arranged teeth, racks meshing wit and moved b the gear, and a nut and screw for each lade actuated by the racksy for changingits an-l gular position. f

4. In a device of the character described, the comblnation of a driving shaft, a casing rigidly 4attached thereto, propeller bladesl carried by the casing,

aY gear splined on the shaft, means for moving the gear axially engagement with the gear and extending to'the shaft, and nut and screw parts for changing the pitch of each blade,fone of said parts being 'moved by the rack and the other being attached to the blade. I

5. In a device of the character described,

Athe combination of a driving shaft, an casing rigidly attached thereto, propeller blades the casing,

pivotally mounted on the casing, a gear ha'v- Iing spirally arranged teeth splined on the shaft, 'means for adjusting the gear, racks yarr-an ed on opposite sides of the 4gear and exten ing perpendi'cularly .to its axis, and

nut and screw parts4 for each blade located in certain of saidgpartsvbeing attached to the racks and the others to the blades. l 1

axes.

6. In a device of the character described, the combination of a driving shaft, a casing which is composed of two principal parts, one of said parts being secured to the shaft, the other having an opening to receive the shaft, the plane of divislon being perpendicular to the shaft, means for uniting the parts of the casing, pivotally supported blades which are anchored against centrifugal forces in the casing, a gear having spirally arranged teeth, an actuating sleeve mountedy in the casing, the sleeve extending through the shaft opening, racks on opposite sides of the gear which mesh therewith, and nut and screw means between the racks and blades for moving them angularly to change their itch. 4

7. n a device of the character described, the combination of a drivin shaft, a casing rigidl mounted thereon w ich is provided with blade supports, a spiral gear splined on the shaft, means for moving the gear axially, racks havin teeth meshing with those on the gear, guides for the rack which lalso form a hollow square to brace the cas- 'blade lspindles and the others to the racks.

9. In a device of the character described, the combination of a driving shaft, a casin ri idly mounted thereon, a spiral gear whic slldes axially of the shaft within the casing, a sleeve which extends outside of the casing for moving the sleeve, actuating means for adjusting the sleeve,

angularly adjustable blades mounted on the casing, and 'nut andscrew parts which are actuated l racks having teeth f which mesh with those of the gear,

by theracks for turning the blades on their In witness whereof, I have hereunto set my hand this 22 day of June, 1918.

"OTTO EF. PERSSON. 

